In the manufacture of semiconductor wafers, various instruments are used to individually move wafers. For example, tweezers are utilized at times. Typically, however, a vacuum-operated apparatus is used for the handling of semiconductor wafers. Such an apparatus includes a vacuum-actuating wand and a replaceable wand tip having a vacuum pocket in evacuation communication with the wand. In operation, the surface of the wand tip associated with the vacuum pocket is brought into contact with a wafer, afterwhich the wafer is maintained against the surface until the vacuum is released.
The spatula-like wand tip is a popular design for the handling of semiconductor wafers and the like. The spatula design generally refers to tips which have a wand attachment segment and a wafer pickup segment that is relatively flat for releasable engagement with a semiconductor wafer. Attempts have been made to manufacture spatula-like wand tips by the mere compressing of one segment of a tube to provide parallel but non-contacting upper and lower sides. A hole cut into the lower side of the compressed segment allows fluid communication with the tubular portion for the evacuation of air. At the end of the compressed segment opposite to attachment segment, the opposed sides must be pressed together, and preferably tightly sealed with a weld joint or solder. Such tips have the advantage of ease of manufacture, but include disadvantages as well. Parallel, non-contacting sides provide a number of areas for the collection of abrasive particles and contaminants, both of which are detrimental to high-yield wafer manufacturing. Moreover, thin-walled tubing is utilized, and the wand tip is therefore susceptible to bending. Bending of the wand tip jeopardizes the vacuum seal integrity since a wafer-contacting surface must be planar.
Thus, in the manufacture of metallic wand tips, the common practice is to insert a blade into the flattened portion of the tip. Such a wand tip is described in U.S. Pat. No. 4,736,508 to Poli et al. The vacuum tip of Poli et al. includes a blade having an axial notch. The blade adds stiffness to the tip to maintain a flat surface for proper vacuum seal to the wafer. The axial notch allows the formation of a passage through the flattened portion to a window formed in one side. While the Poli et al. tip has advantages over the above-described wand tip, great care must be taken to ensure that the blade is securely fixed to the flattened portion and that the inclusion of the blade does not create voids which cause vacuum leakage and can collect contamination. A hole is cut through a side of the flattened portion of the Poli et al. tip for insertion of a brazing material to the inserted blade. Thus, the method of manufacturing the vacuum tip is labor-intensive as compared to the above-described wand tip.
It is an object of the present invention to provide a wand tip and a method of manufacturing the same which significantly reduces the risk of formation of voids, and yet provides a structurally sound member for the handling of semiconductor wafers and the like.